Method of manufacturing shoes



UNITED STATES PATENT OFFICE.

GEORGE E. GREELEY, 0F HUDSON, MASSACHUSETTS.

METHOD OF MANUFACTURING SHOES.

No Drawing.

To all whom it may concern Be it known that I, GEORGE E. GREELEY, a citizen of the United States, residing at Hudson, in the county of Mjddlesex and State of Massachusetts, have invented certain Improvements in Methods of Manufacturin Shoes, of which the following is a speci cation.

This invention relates to methods of manufacturing boots and shoes and is particularly concerned with the treatment of the soles of boots and shoes.

The rapidly increasing price of sole leather has practically compelled the manufacturers of certain of the cheaper lines of shoes, such for instance as rough work shoes,

to use exceedingly poor grades of sole leather stock. This stock is very soft and spongy, becomes pulpy when wet for any great length of time, and has very inferior wearing qualities, particularly if it is subjected to hard wear while wet. It-usually is cut from the necks, bellies and butts of the hides. Soles cut from this stock are not only unsatisfactory to the purchaser of the shoes in which they are incorporated, but they are also unsatisfactory to the manufacturer since they present an exceedingly poor appearance, even in a finished shoe, and much of this stock is so soft that it is unsatisfactory to handle in the various processes of manufacture of the shoe. The present invention is directed to the treatment of sole leather stock of this character with a View to improving the physical characteristics which adapt it for use in shoe soles, and the invention also aims to improve the methods of manufacturing shoes in which stock of this character is used for soles.

After much experimenting with sole leather stock of the character above mentioned, I have found that this stock can be greatly improved by impregnating it with a melted mixture of paralfin and rosin.

- While undoubtedly other ingredients may be used, I prefer to use a mixture consisting of about two parts of parafiin to one of rosin, melting the mixture in a suitable receptacle and maintaining it at a temperature of, say for instance, 280 degrees F. The sole blanks may be mounted in a sole rack of the type commonly used in shoe factories and then submerged in this hot bath. They become sufiicientlg impregnated with it after an immersion 0 from 30 seconds to one Specification of Letters Patent.

Patented May 20, 1919.

Application filed December 28, 1917. Serial No. 209,218.

ordinarily used for this purpose comprises wire members between which the soles are held edgewise in spaced relationship so that they Will drain very thoroughly.

I find that a sole treated in this manner is very much superior to an untreated sole since it loses completely its spongy consistency and is rendered much harder and firmer and is substantially waterproof.- Tests have demonstrated that it is immensely superior to an untreated sole from the standpoint of wear. The treatment therefore completely overcomes many of the disadvantages heretofore experienced with soles made of this soft spongy stock. I find, however, that this treatment renders the soles so hard that a very large percentage of them break or crack in the molding operation. Furthermore, in the attachment of these soles in the usual manner to the uppers of shoes, whether by means of metallic fastenings or by stitches, the stock is liable to check or split between the adjathem in a steam chamber while they are still on racks like those in which they have been placed during the dipping operation. Preferably a temperature of about 120 degrees F., is maintained in this chamber and it is filled with saturated steam or water vapor. After being subjected to the action of this hot vapor for about fifteen minutes, the soles are removed and then are molded while they are still hot and moist. In this condition they are soft enough to mold without breaking or cracking and, in fact, the molding operation seems to improve their quality. These soles retain the shape given to them by the molds-better than do the untreated soles. The soles immediately return again to their hard condition upon cooling As is well understood by those skilled in this art, the soles are laid or temporarily secured in the proper position on the bottom of the shoe by cement, tacks or other fastening means, the nature of which depends largely on the type of shoe being manufactured, preparatory to being permanently secured to the other parts of the shoe. ously it is undesirable to steam the upper of the shoe, and it therefore is impracticable to follow the same process in softening the sole a second time that is followed in softening it preparatory to the molding operation. A convenient means of effecting this second softening operation consists in placing the shoes on a rack or grating, sole downward, immediately over a coil of steam pipes so that the soles will be heated, and then dipping the soles of the shoes for an instant in hot water at, say 120 degrees F., a very few minutes before the attaching operation is to be performed. This process softens up the soles so that not only is all checking or cracking of the sole avoided during the attaching operation, but the machine that performs the attaching operation is enabled to work more rapidly and easily.

The softening of the solo in the manner described does not appear to remove any of the impregnating mixture from the sole. In fact, the softening operations appear to be advantageous since, if the mixture fails to penetrate the entire thickness of the sole thoroughly during the dipping and draining operations, thus leaving a part of the stock in the central portion of the sole that contains less of the mixture of paraffin and rosin than do the other portions, the heating and moistening operations above described appear to effect a more uniform distribution of the mixture in the sole, driving it from the surface into the interior portion of the sole.

The expense added to the manufacture of shoes by this process is trifling compared with the increase in serviceability and wear-- ing qualities that are imparted to the shoe Copies of Obviby it. The material with which the sole is impregnated remains in the sole much longer than do the ordinary waterproofing solutions and consequently the sole retains the qualities that are imparted to it by this treatment until it is substantially worn out. Soles treated in this manner therefore do not become soft and pulpy when the shoes are worn for a considerable length of time in water, as do the untreated soles, and the life of the soles thus is very materially prolonged.

It will readily be understood that the invention not limited to the precise details of the steps above described. The forego-- ing description is intended rather as an explanation of a successful way of practising the invention and it is obvious that the steps may be varied in many particulars while still retaining the essential features of the invention. For instance, the temperatures above mentioned may be varied within reasonable limits while still producing satisfactory results. It is obvious, however, that care should be taken not to subject the stock to too high temperatures, since some kinds of stock burn or become very brittle when subjected to too great a degree of heat and their Wearing qualities are permanently impaired.

What I claim as new is That improvement in the art of manufacturing shoes, which consists in impregnating the shoe sole with a material hard at ordinary temperatures but capable of being settened by heat and which is adapted to increase the wearing and waterproofing properties of the sole but which renders the sole relatively hard at ordinary temperature, softening the sole by subjecting it to heat and moisture. securing the sole to the upper of the shoe while it is so softened, and thereafter allowing the sole to cool and harden.

In testimony whereof I have signed my name to this specification.

GEORGE E. GREELEY.

this patent may be obtained for five cents each, by addressing the Commissioner of Patents Washington, D. G. 

